MacOS X Jaguar was 64-bit capable?

I was watching the PowerMac G5 keynote on youtube, and noticed that it was first released in June 2003! That means, it must be using Jaguar, and since G5 is 64-bit, that means Jaguar must be 64-bit capable?

10.3 has support for more than 4 GB of physical memory addressable by the OS (but not my individual processes)

10.4 has support for 64-bit processing in non-GUI processes

10.5 has support for 64-bit processing in Cocoa GUI applications

Two more:

10.2.7 (G5-only) had a 64-bit version of Accelerate.framework, i.e. for AltiVec (math and vector processing).
And 10.6 has a 64-bit kernel (alongside a 32-bit one), and therefore support for 64-bit kernel extensions.

I read a blog from adobe engineer a while ago about why CS4 won't be 64-bit. He said Apple didn't port the Carbon to 64-bit, only Cocoa is ported to 64-bit, so they couldn't support 64-bit for the CS4.

Now, if that is the case, even Carbon was ported to 64-bit, CS4 still shouldn't be able to access more than 64-bit, no?